APLIKASI PROGRAM SIMLAR V.10 GUNA MEMETAKAN DAERAH RAWAN BANJIR LAHAR PADA KALI PUTIH.

Indonesia, which consists of a cluster islands has a very high potential for disaster and also have varied aspects type of disaster. One of them was a disaster due to lava/debris flow or commonly called catastrophic sediment (sediment related disaster). Efforts to cope with catastrophic sediment has been developed. One of them is the structure of the Sabo building technology to control the sediment flow. This study aims is to determine the effectiveness of Sabo Building on the results of the lava/debris simulation as well as to estimate and mapping the hazard/flood prone debris around Watershed (DAS) of Kali Putih, for the development " Early Warning System ", which will reduce the negative impact of disaster.
This was an exploratory study using empirical data from the Puslitbang Sabo Hall Yogyakarta as a Primary data. Identification of the marfologi type using Rosgen method, and Nakayashu method to determine the flood hydrograph.
Research results of the Kali Putih marfologi type by the slope of the river are classified as B, D, G type, and based on the value of entrenchement ratio are classified as C, D, E type, while by the W/D Ratio are classified as B, C & F type, which has rate of erosion and high sediment supply to discharge flood peak of 18.21 m3/s based on calculations using the Nakayashu method of flood hydrograph. Simulation results show the effectiveness of Sabo Building looks less than optimal because it can not withstand the debris (debris flow)/lava flow sediment that occur, so that the lava flow/debris flow runoff into the residential area. In addition, due to the location of the Sabo building that is on the Magelang-Yogyakarta road resulted inland transport access paralyzed on lava flood of Merapi eruption in last 2010. Calibration results of simulation simlar V.1.0 applications and maps of the affected villages from BNPB, show that the areas that have great potential flooding due to runoff lava flow/debris (debris flow) are Jumoyo Village, Village Sucen, and Seloboro Village, and the Village Gulon. After knowing the vulnerable points of lava flood/debris (Debris Flow), we expected "Early Warning" can be done for people who living in the areas/villages. so that in times when a disaster happens people have to anticipate the possibility of bad things that can be life-threatening.